The present invention is related to monitoring signals in a communications network and, more particularly, to measuring service provider service quality on a communications network.
Common channel signaling networks, such as the Signaling System Seven (SS7) based signal system, use dedicated channels to pass digital messages between systems for call setup, call control, call routing, and other functions. These dedicated signaling channels are part of a network that is separate from the network that carries the actual voice and data signals. An SS7 network is a separate switching system which is used prior to, during, and at the end of an actual voice or data call. The SS7 network is used to route control information. Whenever two switches or elements have to pass call control information during or prior to a phone call, they pass this data via the SS7 signaling network.
There are three basic types of network node elements in an SS7 network. One of them is the Service Switching Point (SSP), which may be a central office switch, a tandem switch or an end office switch. A second principal node element is the Service Control Point (SCP). An SCP acts as a database query server for the rest of the network. An SCP is used in such applications as translating ported telephone numbers, routing 800 calls, tracking roamers in a cellular network, and Alternate Billing Service/Line Identification Database services (or ABS/LIDB) which provide operator-type services. The third principal node element is the Signal Transfer point (STP). An STP is essentially a packet switch that routes the messages from SSPs and SCPs to SSPs and SCPs.
It is possible to combine these three different types of nodes into a single node. However, in North America, they are typically not combined. An SSP performs only switch functions, an SCP only control functions, and an STP only signal transfer functions. In European telecommunications systems, all of these different functions may be combined into one node.
The SS7 network carries a great deal of information and is extremely critical to the operation of the phone system. If an SS7 network is not functioning, or if portions of it are not operating, the phone system simply cannot deliver phone calls, even though all of the voice circuits are operating properly. The capacity and complexity of the SS7 network is small in terms of circuitry and bandwidth utilized by an end user compared to previous voice and data networks. The circuitry of the SS7 network is therefore much more critical. The actual elements in the SS7 network do not provide all the information required in network operations to manage and to determine the health and state of an SS7 network. It is therefore necessary for the telephone industry to deploy surveillance equipment to monitor the links connecting the nodes of the SS7 network.
The topology of the network is such that STPs are typically deployed in a mated pair configuration at geographically separate locations. Connected to a mated pair of STPs will be a set of SSPs and SCPs. This conglomeration of SSPs, SCPs and mated Pair STPs is called a cluster. Clusters are then connected by D-Quad links between STP mated pairs. The mated pair configuration system is not required and it is not used in all communications systems capable of employing the present invention.
When any call, transaction or message is sent between two different devices on the network, it is often the case that the messages going from switch A to switch B travel one route on the network while the messages going from switch B to switch A travel a different route. The network surveillance equipment that monitors the link is designed to capture and correlate as much signaling information as possible regardless of network activity. Because of the different data paths that messages may take, it is difficult to do this correlation above what is called the transport layer when monitoring links at the STP sites. An example of an application level problem would be where a subscriber has a problem getting his/her calls delivered. The telephone company may attempt to fix the problem by doing a trace of all data pertaining to that subscriber""s phone number, but the data may not all be located at one point. The data may be all in one STP, or split in some fashion, partially in one STP and partially in the other STP of a mated pair, which may be in a different city many miles away.
These and other objects, features and technical advantages are achieved by a system and method in which a monitoring network, having network monitors that capture messages, such as message signal units (MSUs), from links in a communications network, correlates the messages into call or transaction records for further processing. The monitors have a plurality of processors for processing the captured messages. The processors may run any of a number of message or record processing applications. In the present invention, a quality assurance application provides an integrated platform for message tracking on a per customer and/or a per service provider basis. The tracked messages may be part of one of a number of message protocols, such as Integrated Services Digital Networkxe2x80x94User Part (ISUP), Telephone User Part (TUP), Network User Part (TUP), Transaction Capabilities Application Part (TCAP), Advanced Intelligent Network (AIN) or Integrated Network Application Part (INAP) calls or transactions. The quality assurance application is ideal for larger networks or for evaluating service quality of application-layer services, such as INAP, Global System for Mobile Communications (GSM), AIN, IS-41 and 800LIDB/CLASS.
In a preferred embodiment, the quality assurance application runs on a server that is external to the network monitoring system. The monitoring system provides data to the external server in the form of Call Detail Records (CDRs). The quality assurance application tracks the quality of service that is provided to customers on a particular communications network. The present invention allows customers, service providers and others to monitor how a service is performing not only within the network infrastructure, but also how well that service is working on a call-by-call, customer-by-customer basis. Additionally, the present invention allows service providers to efficiently manage network services without requiring an increased support staff.
The quality assurance application runs on an independent server and processes CDRs that are received from the monitoring system. In a preferred embodiment, individual monitoring units exchange and correlate messages into call or transaction records. The monitoring unit then filters the records using a CDR profile to determine which records, and which messages, should be combined to form the CDR. The monitoring units then transmit the CDRs directly to the external server. In an alternative embodiment, some other entity in the monitoring system, such as a central server, may generate and forward CDRs to the independent quality assurance application.
The quality assurance application provides service quality analysis tools and reports. The application generates historical statistic reporting for circuit-based services or for application-layer services. The statistics are maintained in a database which can be accessed to generate quality of service reports. When used to monitor service on an SS7 network, the present invention maintains statistics for all ISUP/TUP circuit-based calls. Statistics are maintained by called number, calling number and translated number. Users may generate reports for the statistical information by accessing the database through a workstation. The reports may be customized using various indices, such as by called, calling, or translated number.
Additional statistics may be monitored and other reports may be created for other communications networks or protocols. For example, TCAP statistics may be monitored and reports may be generated by service as well as by called, calling and translated number. Statistics for other application layer services could also be monitored. Such as for INAP, GSM, AIN, IS-41 and 800/LIDB/CLASS services.
Communications network monitoring equipment which may be used in conjunction with the present invention is disclosed in U.S. Pat. No. 5,592,530, entitled TELEPHONE SWITCH DUAL MONITORS; and in pending patent applications assigned Ser. No. 09/057,940, entitled SYSTEM AND METHOD FOR MONITORING PERFORMANCE STATISTICS IN A COMMUNICATIONS NETWORK; Ser. No. 09/092,428 entitled SYSTEM AND METHOD FOR DETECTING HIGH MESSAGE TRAFFIC LEVELS IN A COMMUNICATIONS NETWORK; Ser. No. 09/092,699 entitled SYSTEM AND METHOD FOR SIGNAL UNIT DATA STORAGE AND POST CAPTURE CALL TRACE IN A COMMUNICATIONS NETWORK; Ser. No. 09/092,256 entitled SYSTEM AND METHOD FOR GENERATING QUALITY OF SERVICE STATISTICS FOR AN INTERNATIONAL COMMUNICATIONS NETWORK; and Ser. No. 09/092,771 entitled SYSTEM AND METHOD FOR CORRELATING TRANSACTION MESSAGES IN A COMMUNICATIONS NETWORK, filed Jun. 5, 1998 the disclosures of which are hereby incorporated by reference herein. These references and the present application are commonly assigned.
It is a feature of the present invention to track performance statistics in a communications network. The invention provides statistical reports which show how many calls were successfully connected to the called number and how many calls were dropped. The reports allow users to determine the reason for call failures and to identify portions of the network which are not operating properly.
It is another feature of the present invention to allow customers, service providers and third parties with the ability to monitor a the quality of service on a particular communications network. Customers can use the statistical reports to determine their service provider""s quality of service. The present system can also be used by customers to determine if the customers"" systems are providing adequate service. For example, call centers can use the statistical data to determine whether additional agents are needed to answer calls that have been dropped due to busy lines. Service providers may use the information to monitor the service provided by their network and to identify failure points on the network. Service providers can also monitor the quality of service provided by other service providers on other networks.
It is an additional feature of the invention to generate statistical reports for called, calling or translated numbers or for services. Additionally, users can designate particular link sets to be used for the statistical report generation. As a result, only those monitors capturing messages from the designated link sets will send CDRs to the quality of service application.
It is another feature of the present invention to provide statistical reports in real-time on a network-wide basis for both calls and transactions. Historical data is also stored to a database for later recall by the user.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.